• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2002.05a
• /
• pp.210-214
• /
• 2002

집중도 변화와 정신피로는 정의 방향의 평가와 부의 방향의 평가가 있으며, 작업 수행시의 집중변화와 정신피로의 평가는 정의 방향보다 부의 방향으로의 평가가 용이하다. 따라서, 저자들은 먼저 피험자에게 부가할 정신작업부하로 난이도 조정이 용이한 연산작업을 사용하여 작업수행시 가장 높은 집중을 요구하는 하나의 난이도를 선정하고 피험자에게 반복 수행시키면서 생리량과 심리량을 동시에 측정하였다. 측정된 생리량은 뇌파, 심전도, 호흡, 맥파, 말초피부온이며 심리량은 저자들이 개발한 정신피로설문지를 사용하였다. 분석결과 작업수행시 심박변화율의 전력스펙트럼 MF/(LF+HF)비가 감소하였으며, 작업이 반복됨에 따라 집중이 저하되고 정신피로가 증가하였다. 특히, 뇌파의 beta파와 호흡간격이 집중도의 변화를 말초피부온이 정신피로를 잘 반영하였다.

• Journal of the KSME
• /
• v.22 no.1
• /
• pp.9-14
• /
• 1982

복합재료를 이용하여 부품제작을 한 후 어떠한 결합방법을 채택할 것인가를 결정할 때 고려해 야할 점을 기계적 결합법과 접착결합법을 비교하여 검토하였다. 기계적 결합은 하중을 많이 받고 분해 및 결합이 자주 예상되는 부품에 채택해야 할 것이며 복합재료의 특성을 고려하여 보강 시에 부착하는 평판의 섬유방향은 가급적 드릴구멍주위를 부드럽게 하여 응력집중을 낮출 수 있으며 하중의 종류에 따라 적층의 섬유방향을 조절함으로서 응력집중을 조절할 수 있다. 드릴 구멍 주위인 파손은 평판의 폭과 구멍의 직경등이 크게 작용함으로 강도해석을 할 경우에 응력 해석을 한 후 허용응력등을 결정해야할 것이다. 접착졀합법은 작업이 간단하나 신뢰도가 떨어지 므로 하중을 많이 받는 구조물에의 사용에 주의를 요하며 설계방법도 매우 다양하게 제안되어 있어 선택함에 있어 하중 환경조건등을 점검해야할 것이다. 접착결합법은 드릴구멍같은 불연속 성을 갖지 않기 때문에 응력집중이 생기지 않으나 접착층의 길이등 기하학적 형상에 따라 다르게 나타남으로 잡착층의 분리가 일어나지 않도록 설계되어야 한다. 특히 복합재료의 이방성인 성 질을 감안하여 접착층에 이웃하는 피접착층의 섬유방향에 주의해야 하며 층간응력이 파손에 미 치는 영향을 고려하여 설계에 임해야 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.10
• /
• pp.1036-1043
• /
• 2003

In this paper, novel lumped equivalent circuits for a conventional parallel directional coupler are proposed. This novel equivalent circuits only have self inductance and self capacitance, so we can design exact lumped equivalent circuit. The equivalent circuit and design formula for the presented lumped element coupler is derived based on the even- and odd-mode properties of a parallel-coupled line. By using the derived design formula, we have designed the 3 dB and 10 dB lumped element directional couplers at the center frequency of 100 MHz and 2 GHz, respectively a chip type directional coupler has been designed with multilayer configurations by employing commercial EM simulator. Designed chip-type directional couplers have a 3 dB-coupling value at the center frequency of 2 GHz and fabricated lumped directional coupler on fr4 organic substrate has a 3 dB, 10 dB-coupling values at the center frequency of 100 MHz. Excellent agreements between simulation results and measurement results on the designed directional couplers show the validity of this paper. Furthermore, in order to adapt to multi-layer process such as Low Temperature Cofired Ceramic (LTCC), chip-type lumped element couplers have been designed by using this method.

• Science of Emotion and Sensibility
• /
• v.14 no.3
• /
• pp.395-402
• /
• 2011

As the consumer market for odor products grows, companies producing healthcare products are beginning to pay more attention to the emotional aspect of an odor product in order to differentiate their products from competitors. In the following research, the affective effect of odor product was investigated while focusing on relaxation and working contexts using orange and pine scents, since these are typical odors in current domestic market. Two empirical studies were carried out. First, in experiment I, 18 subjects, all of whom were university students, spent 20 minutes sitting comfortably on a sofa while electrocardiogram assessments were made. After a five-minute break, in experiment II, the same subjects were provided with both arithmetic and geometric questions and their electroencephalogram readings was recorded from eight channels. All subjects participated in three sessions - no odor, an orange scent, and then a pine scent - with a minimum time interval of 24 hours. The results show that in the context of a pine scent, both the activation ratio of subjects' parasympathetic system and those of the Sensory Motor Rhythm waves and Mid Beta waves were at the highest peak. Therefore, the pine scent helped the subjects to feel more comfortable and more focused at the same time. In other words, it gave them a state of meditated attention. In addition, it was found that the right brain was activated twice the intensity when the subjects worked through the geometric questions, whereas both sides of the brain were activated in equal magnitude during the process of arithmetic tasks. This replicates previous studies of the functional aspect of the right brain - being responsible for spatial and creative thinking.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2010.10a
• /
• pp.209-211
• /
• 2010

본 연구는 싱가폴 VTS의 현장을 직접 방문하여 파악한 시설현황과 제도를 위주로 기술하였다. 관제사의 선발 시스템 및 교육 훈련 제도가 어떻게 운용되고 있는지에 대해서도 알아보았다. 또한 현재 싱가폴 VTS에서 추구하고 있는 차세대 VTS에 대한 방향에 초점을 맞추어 우리가 벤치마킹할 요소들에 대해서 집중적으로 검토해보고 우리나라 VTS의 발전방향을 모색하여 보았다.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.5 no.1
• /
• pp.11-18
• /
• 2002

Directional breaking waves are generated by the component wave focusing both in direction and frequency based on constant wave steepness and constant wave amplitude spectrum models. The generated breaking waves are classified in the incipient, single and multi breaking waves. The characteristics of directional breaking waves are investigated in terms of surface profile parameters of wave crest steepness and asymmetry. The evolution of breaking wave characteristics is analyzed in a view of focusing efficiency. It shows that the front steepness and vertical asymmetry play an important role in breaking process, while the crest rear steepness and horizontal asymmetry are nearly constant during the process. The superposition of directional components greatly enhances the focusing efficiency and it suggests that characteristics of directional breaking waves may significantly different from uni-directional ones.

• Journal of Internet Computing and Services
• /
• v.12 no.4
• /
• pp.51-59
• /
• 2011

The purpose of this study is to provide relevant directions of media industry regulation and policy by analyzing the relationship between market concentration and performance in global pay TV markets. The market concentration has long been regulated in the media industry under the belief that it harms market efficiency and cultural diversity. As the global media market is undergoing significant chance accelerated by the advance of technology, it is necessary to examine the feasibility of this long myth. The data are collected from global 17 pay TV markets and analyzed to see whether the highly concentrated markets by a single player result in higher price and slower service penetration. The result indicates that the price is not escalated and the penetration is not limited even in the markets where a dominant player takes high market share. It implies that more diverse factors other than the market concentration affect the market performance and that maintaining strict regulation of the market concentration is likely to have negative effect on technology innovation.

• Journal of Korea Fair Competition Federation
• /
• no.49
• /
• pp.13-17
• /
• 1999

• Journal of Korea Fair Competition Federation
• /
• no.49
• /
• pp.18-22
• /
• 1999

• Monthly Duck's Village
• /
• s.136
• /
• pp.34-43
• /
• 2014